Question | Answer |
What hormone does the thyroid gland produce? | Thyroxine |
Define the term Exocrine | Secretes substances through a duct (not hormones) |
Define the term Endocrine | Secretes substances (hormones) directly into the blood stream |
What are hormones? | Chemical messengers |
What type of gland produces hormones? | Endocrine glands |
What do we call the areas of the body affected by hormones? | Target cell or target tissue |
What hormones are produced in the Pancreas? | Insulin and Glucagon |
What does insulin do? | Lowers glucose levels |
What does Glucagon do? | Raises glucose levels |
What hormones are produced in the Ovaries? | Oestrogen and Progesterone |
What hormone is produced in the Testis? | Testosterone |
What do target cells need to receive the hormone? | A correct receptor |
Where are receptors on cells found? | In the cell membrane |
What are receptors likely to be made of? | Proteins |
What are steroid hormones made from? | Lipid molecules often adapted from cholesterol. |
Is the steroid hormone able to pass through the membrane? | Yes, it goes into the cell |
Where will the steroid hormone found the receptor? | In the cytoplasm of the cell |
What does the hormone act on in the cell? | The DNA |
Why can steroid hormones pass through a plasma membrane? | They are lipid soluble |
Give an example of a steroid hormone | Sex hormones |
What is a peptide hormone made from? | Protein molecules |
What happens to the peptide hormone when it reaches the cell surface? | The hormone binds to the membrane |
What is required for a peptide hormone to deliver a message within the cell? | A second messenger |
What is meant by a secondary messanger? | It receives and transfers a message from the hormone to within the cell |
Why can peptide hormones not pass through a plasma membrane? | They are not lipid soluble and are the wrong shape to get through the channels |
Give 3 examples of peptide hormones | Adrenaline, Insulin and Glucagon |
What is an adrenaline molecule derived from? | Amino acids |
What is the name of the enzyme associated with the receptor for adrenaline? | Adenyl cyclase enzyme |
What happens to the enzyme when the adrenaline binds? | It becomes active and changes shape. |
What does the first messenger do? (the hormone) | Find the target cell and binds to the receptor |
What are the two main regions called on the adrenal glands? | The medulla and the cortex |
What 5 other functions do the adrenal glands help to carry out? | Increase sweating, increase heart-rate, hairs stand on end, higher blood pressure, dilate bronchioles (to allow in more oxygen) |
What is the master gland? | Pituitory gland |
What is the control centre near the pituitory gland? | The Hypothalamus |
What is the effect called when small amounts of one hormone is released from the hypothalamus resulting in production of the final hormone | Cascade Effect |
What hormone does the pituitory gland produce the regulates water balance? | ADH |